Peter Davison (The Doctor)
Nicola Bryan (Peri)
Maureen Oakley (Pilot Susan Roberts)
Robert Jezek (Commander Lee Forbes)
Stephen Fewell (Paul Webster)
Georgia Mofftt (Tanya Webster)
Hylton Collins (Sub-Commander Sstast)
Matthew Brenher (Lord Zzarl)
Alistair Lock (Zizmar)
Jason Haigh-Ellery (Sskann)
Gary Russell (Razzburr)